OPA-6566

OPA-6566 is a novel small molecule adenosine A2A receptor agonist developed for ophthalmic use, specifically as a treatment for open-angle glaucoma and ocular hypertension. The drug was discovered by the Ako Research Institute at Otsuka Pharmaceutical and later co-developed with Acucela (now Kubota Vision). Its mechanism of action involves stimulating aqueous humor outflow via the trabecular meshwork through activation of the adenosine A2A receptor, resulting in lowered intraocular pressure—a new approach compared to conventional glaucoma medications. Clinical development reached Phase 1/2 trials but was discontinued before approval[1][3][5].